Athletics chief Sebastian Coe described the sight of Usain Bolt pulling up injured in the final race of his glittering career as "horrible."

The Jamaican collapsed to the track on the final leg of the 4x100 metres relay at the World Championships in London on Saturday.

It was a sad way for the 19-time global champion to bow out.

Coe, president of world athletics governing body the IAAF, said: "The athlete in me tells me it's a devastating moment if you're in mid-race and something starts not to work, it's horrible.

"Whether the Jamaican team were in a medal position or not, the reality of it is you don't want to see anybody not being to be able to fulfil what they warmed up to do and what they prepared to do."

But Coe knows it is off the track as much as on it that athletics will miss the larger-than-life Bolt.

"What we are going to miss about Usain Bolt is not the three back-to-back Olympic Games or the clutch of world records or the medals, it's going to be because he has an opinion, he has a view, he fills a room," he said.

"We have some really terrific talent that's identified themselves at these championships, but that's not the same as filling that void."

On the track last night, Caster Semenya blitzed the field in the final 200 metres of the 800 metres final to take gold in a new South African record of one minute 55.16 seconds which looked almost effortless.

Elijah Manangoi of Kenya took gold in the 1500 metres ahead of compatriot Timothy Cheruiyot. Filip Ingebrigtsen of Norway, took bronze by diving dramatically over the line, edging beyond Spain's Adel Mechaal with the unorthodox manoeuvre.